High Altitude Weather Balloon Explorer II

Warwick wove material for record setting weather balloon

Warwick Mills wove the material used for the high-altitude helium weather balloon launched by National Geographic in 1935.

The Explorer II was designed to study conditions in the highest reaches of the atmosphere. It had an envelope of 3,700,000 cubic feet (104,772 cubic meters) and was considered the first helium balloon.

Sponsored by the National Geographic Society and the US Army Air Corps, the stratosphere balloon was flown in November of 1935 from the Stratobowl located in South Dakota near Mount Rushmore, which was used on numerous occasions during the 1930s to launch balloons for scientific research.

The balloon rose to a height of 72,395 feet (22,066 m), a world record for altitude that stood for more than 20 years.

Explorer II

Stevens was the chief of the Army Air Corps photography lab at Wright Field, Ohio. The photographs taken from the high-altitude airship demonstrated the enormous potential for long-range reconnaissance from high-altitude balloons, as well as clearly showed the curvature of the earth.

The flight was a huge success for both the US Army and the National Geographic Society.

Today, Explorer II is on display at the South Dakota Air and Space Museum. The museum is at the Ellsworth Air Force Base in Box Elder, South Dakota.